SCHLADMING, Austria - All it took was a moment. Lindsey Vonn landed hard and tumbled face first with a piercing shriek.

Just like that, the star American skier was on the ground with two torn ligaments in her right knee and a broken bone in her lower leg.

The cascading fall down the slope during the super-G at the world championships Tuesday knocked out the four-time World Cup champion for the rest of the season, the latest and most serious in a string of injuries for Vonn at skiing's biggest events.

The U.S. team said in a statement it expects her back for the next World Cup season and the 2014 Sochi Olympics, which start a year from this week.

The harrowing accident came after Vonn was lifted into the air off a jump in the opening race at the championships. As she hit the ground, her right leg gave way and she spun down face first, throwing an arm out to protect herself. She ended up on her back as she smashed through a gate.

For 12 minutes, Vonn lay on the snow getting medical treatment before being airlifted by helicopter to a hospital in Schladming.

Vonn tore her anterior cruciate ligament and medial collateral ligament in her right knee, U.S. ski team medical director Kyle Wilkens said in a statement. The broken bone was described as a "lateral tibial plateau fracture."

Christian Kaulfersch, the assistant medical director at the worlds, said Vonn left the Schladming hospital on Tuesday afternoon and will have surgery in another hospital.

"She first wanted to go back to the team hotel to mentally deal with all what has happened," Kaulfersch said.

Vonn's father, Alan Kildow, spoke with her by phone and said that she's, "mad at the way things turned out." His daughter told him that she landed in a clump of sugar snow, or ice crystals, that caused her to fall forward, he said.

Kildow said that surgery could take place as soon as this weekend, likely at the Steadman Clinic, in Vail, Colo. Recovery time varies, according to Dr. Tom Hackett, an orthopedic surgeon at the clinic and the team physician for the U.S. snowboard squad.

But Vonn could be looking at six-to-eight months before she's back on skis.

"It's not like at six months you say, 'OK, you can get back on a super-G course," Hackett said. "There's a progression to getting back on skis, getting back to taking some easy runs, getting back to some gates, and working your way back to some steeper terrain. There's a whole return to snow progression that we've developed over many years."

Time enough to get back for Sochi?

"I think so," Hackett said.

"There's a really good chance she could come back as strong as ever."

Comebacks are nothing new for Vonn, who has also been afflicted by injuries at her last six major championships.

This one, however, could prove the biggest test yet for the 28-year-old who won the downhill at the 2010 Vancouver Olympics.